Power amp models and the lack thereof

[jay mitchell]

It’s interesting, and I guess it doesn’t apply to the preamps

You could access preamp only in an Axe-Fx by setting power amp sag to zero. That applies to first- and second-generation Axe-Fxs. I don't know about the third.

 

[Frodebro]

You could access get preamp only in an Axe-Fx by setting power amp sag to zero. That applies to first- and second-generation Axe-Fxs. I don't know about the third.

Third generation has the option to disable power amp modeling altogether, which has been useful when running into a tube power amp.

 

[jay mitchell]

They're not bad. Been running some analog preamps through them with very decent results.

That was one of the intended uses: as power amp modeling/IR convolution on a pedalboard.

 

[jay mitchell]

Third generation has the option to disable power amp modeling altogether,

According to the manuals for the first two generation units, setting sag to zero did exactly that: disabled power amp modeling.

 

[laxu]

Hotone Ampero 2 has a poweramp model. It's quite alright. It lets you pick powertube type, adjust sag, negative fb and B+ response, presence and resonance.

Personally I've never been too interested in separate preamp and poweramp models. Never had a usecase for them beyond testing things.

 

[Frodebro]

Hotone Ampero 2 has a poweramp model. It's quite alright. It lets you pick powertube type, adjust sag, negative fb and B+ response, presence and resonance.

Personally I've never been too interested in separate preamp and poweramp models. Never had a usecase for them beyond testing things.

The primary use would be people who want to run an external preamp, then use the modeler for power amp and IR.

 

[yek]

You could access preamp only in an Axe-Fx by setting power amp sag to zero. That applies to first- and second-generation Axe-Fxs. I don't know about the third.

These days there's a dedicated Power Amp Modeling ON/OFF parameter in the Amp block.

 

[yek]

Fractal Audio:

"If you only need power amp modeling, for example when using an external pre-amp through the Axe-Fx, use the Tube Pre model. It uses the Vintage tonestack which is flat when the tone controls are at noon."

 

[laxu]

The primary use would be people who want to run an external preamp, then use the modeler for power amp and IR.

I have never found tube preamps from my amps to do anything that I could not get from the digital modeler on its own. Tube preamp modeling has been good for ages.

Last week I tried some Tonex captures of the old Yamaha DG-1000 preamp from 1997. I had the DG80 1x12 combo (1998) so I'm very familiar with that sound. The captures of the preamp with modern IRs sounded just great and were fun to play. Are modern modelers better? For sure, but the point is that preamp modeling even in 1997 was not terrible at all!

But if you want to run a preamp pedal or rack unit, today the most sensible poweramp+cab sim solution would probably be the Tonex One with a poweramp capture loaded. It's tiny and cheap. I have no idea if it can handle line level signal from a rack preamp tho.

 

[synthpenguin]

I have never found tube preamps from my amps to do anything that I could not get from the digital modeler on its own. Tube preamp modeling has been good for ages.

I agree, except about how they interact with boosts / loud drive pedals. I grabbed a tube preamp specifically because I got a little into making DIY pedals, which got me back into hitting an amp with really loud pedals. It’s very annoying to gain stage this with digital, even if it’s possible (at the expense of upping the noise floor). With a tube pre it just works.

If you’re working primarily in digital as far as drive pedals, or are only using external drive pedals for small boosts or around unity volume, I don’t think it’s really worth it, I agree.

This is what I was doing previously, only doing boosts internally, and it worked great. Not quite as fun (for me) though, especially when I suddenly have all these loud fuzzes and stuff lol

ETA: I will say that my primary experience with this with dedicated hardware (vs audio interface > computer) is Helix. Maybe Fractal inputs are less sensitive in a way where this is moot, I’m not sure.

But if you want to run a preamp pedal or rack unit, today the most sensible poweramp+cab sim solution would probably be the Tonex One with a poweramp capture loaded. It's tiny and cheap. I have no idea if it can handle line level signal from a rack preamp tho.

Yes, I’ve been doing this and it works great. It’s the only thing I use the Tonex for so it’s sort of annoying to need it just for that, but it does sound good.

The input can be sensitive, but basically you just lower the preamp output until there is no clipping of the Tonex (while the preamp is being pushed hard), then lower it a little more, then up the Tonex’s gain to compensate. In this case, it doesn’t really introduce much perceptible noise.

 

[Frodebro]

I have never found tube preamps from my amps to do anything that I could not get from the digital modeler on its own. Tube preamp modeling has been good for ages.

Last week I tried some Tonex captures of the old Yamaha DG-1000 preamp from 1997. I had the DG80 1x12 combo (1998) so I'm very familiar with that sound. The captures of the preamp with modern IRs sounded just great and were fun to play. Are modern modelers better? For sure, but the point is that preamp modeling even in 1997 was not terrible at all!

But if you want to run a preamp pedal or rack unit, today the most sensible poweramp+cab sim solution would probably be the Tonex One with a poweramp capture loaded. It's tiny and cheap. I have no idea if it can handle line level signal from a rack preamp tho.

I still have a DG-1000. It still is fun to goof around with, and wouldn’t be worth the hassle of trying to sell. And it does sound good…

 

[Desertdweller]

I can’t believe this is still something that doesn’t exist after all these years of people wanting it and asking for it

I always wished there was a power amp model in my AxeFX so I could put a Triaxis in the rack with it

Agreed. My Synergy modules sound better using Two Notes Wall of Sound power amp modeling than they do going into the FM9 and using DynaCabs. It would be great to get some amp models of Marshall, Fryette, and Mesa power amps, completely devoid of preamp circuits.

 

[laxu]

I still have a DG-1000. It still is fun to goof around with, and wouldn’t be worth the hassle of trying to sell. And it does sound good…

You should dig it out and make some captures of it! There's not a whole lot of them on Tonex and none on Tone3000 for NAM.

 

[Alex Kenivel]

Fractal Audio:

"If you only need power amp modeling, for example when using an external pre-amp through the Axe-Fx, use the Tube Pre model. It uses the Vintage tonestack which is flat when the tone controls are at noon."

This works pretty well. In my 4CM preset I use with my EVH Stealth I have a path that breaks off into the Tube Pre and Cab Block so I can run a direct signal along with the amp/cab.

 

[Elric]

Hotone Ampero 2 has a poweramp model. It's quite alright. It lets you pick powertube type, adjust sag, negative fb and B+ response, presence and resonance.

A number of cab pedals do too, IIRC. It’s seems like a common feature to me, on those kinds of devices. Mooer Radar, Two Notes stuff (CAB M+), Nux Solid Studio, etc which makes it even weirder that modeler designers omit it. I guess they know those boxes are likely to see a preamp or AIAB direct out.

There’s a standalone Analog one Axion PAE-1 and 2. The ToneX One could easily be dedicated for such a task.

I agree that it’s weird that the big ‘All-In-One’ MFX don’t have it built-in. I remember loving that feature on the Atomic as a pretty big preamp fan.

On the Fractal it’s pretty common to use the ‘Tube Pre’ model which is Neutral. See video below.

I use the Tube Pre alot with the Syn and will then copy all the power amp settings from one of the other models, like say the ‘Bogner Uberschall’ and then tweak from there and then save as block when I am loving it. Now that I have a bunch of reactive loads I don’t use it quite so much, though.

 

[Sascha Franck]

Fwiw, as absurd as it might seem, one of the oldest standalone IR loaders, namely the AMT Pangaea, has separate power amp modeling. I have never seriously tested it, but will do so one day.

 

[synthpenguin]

Fractal Audio:

"If you only need power amp modeling, for example when using an external pre-amp through the Axe-Fx, use the Tube Pre model. It uses the Vintage tonestack which is flat when the tone controls are at noon."

This works pretty well. In my 4CM preset I use with my EVH Stealth I have a path that breaks off into the Tube Pre and Cab Block so I can run a direct signal along with the amp/cab.

On the Fractal it’s pretty common to use the ‘Tube Pre’ model which is Neutral. See video below.

I use the Tube Pre alot with the Syn and will then copy all the power amp settings from one of the other models, like say the ‘Bogner Uberschall’ and then tweak from there and then save as block when I am loving it. Now that I have a bunch of reactive loads I don’t use it quite so much, though.

I’d love to try this. I’ve tried similar approaches with Helix and had results that only really worked for me when not actually trying to push the “power amp”, but ofc with Helix you can’t swap out the preamp or get a flat tonestack like that—you have to sort of fake it with EQ settings + extra EQ blocks.

 

[synthpenguin]

Fwiw, as absurd as it might seem, one of the oldest standalone IR loaders, namely the AMT Pangaea, has separate power amp modeling. I have never seriously tested it, but will do so one day.

Interesting!

And yeah, I haven’t tried it on the Two Notes Opus directly, but the software version of the TSM power amp sim on there is excellent.

 

[Whizzinby]

A number of cab pedals do too, IIRC. It’s seems like a common feature to me, on those kinds of devices. Mooer Radar, Two Notes stuff (CAB M+), Nux Solid Studio, etc which makes it even weirder that modeler designers omit it. I guess they know those boxes are likely to see a preamp or AIAB direct out.

There’s a standalone Analog one Axion PAE-1 and 2. The ToneX One could easily be dedicated for such a task.

I agree that it’s weird that the big ‘All-In-One’ MFX don’t have it built-in. I remember loving that feature on the Atomic as a pretty big preamp fan.

On the Fractal it’s pretty common to use the ‘Tube Pre’ model which is Neutral. See video below.

I use the Tube Pre alot with the Syn and will then copy all the power amp settings from one of the other models, like say the ‘Bogner Uberschall’ and then tweak from there and then save as block when I am loving it. Now that I have a bunch of reactive loads I don’t use it quite so much, though.

Yeah, I spent a rainy afternoon creating Tube-Pre PA’s for all the major amp types. It makes it cool to mix and match pre-amps to something appropriate. Pretty easy to do, albeit tedious.

That said, FAS should absolutely sprinkle the fairy dust over some dedicated rack PA classics. (VHT 2150, Mesa 2/90, Marshall 9200 etc.) I have a hard time believing that would in some way jeopardize the FAS modeling methodology.

Maybe there just aren’t many of us still wanting to do the Fantasy Rack Build thing.

 

[2112]

Tube pre + impedance curve of choice is a very quick way to get some power amp mojo going on.